Update ConstrainedWindowViews appearance according to mock

ui/views/controls/button/chrome_style.h

Index: ui/views/controls/button/chrome_style.h
diff --git a/ui/views/controls/button/chrome_style.h b/ui/views/controls/button/chrome_style.h
new file mode 100644
index 0000000000000000000000000000000000000000..80b517e92d6aa51cc6b1a37700445355c64591b3
--- /dev/null
+++ b/ui/views/controls/button/chrome_style.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_VIEWS_CONTROLS_BUTTON_CHROME_STYLE_H_
+#define UI_VIEWS_CONTROLS_BUTTON_CHROME_STYLE_H_
+
+#include "ui/views/controls/button/text_button.h"
+
+namespace views {
+
+// Apply button settings to produce a style similar to Chrome WebUI.
+VIEWS_EXPORT void ApplyChromeStyle(TextButton* button);
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CONTROLS_BUTTON_CHROME_STYLE_H_